/*
* Copyright 2017 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.errorprone.bugpatterns;
import static com.google.errorprone.BugPattern.Category.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.matchers.Matchers.anyOf;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.NewClassTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Types;
import java.util.List;
/**
* Points out on creation of Set and HashMap of type java.net.URL.
*
* <p>equals() and hashCode() of java.net.URL class make blocking internet connections.
*
* @author bhagwani@google.com (Sumit Bhagwani)
*/
@BugPattern(
name = "URLEqualsHashCode",
summary =
"Creation of a Set/HashSet/HashMap of java.net.URL."
+ " equals() and hashCode() of java.net.URL class make blocking internet connections.",
category = JDK,
severity = WARNING
)
public class URLEqualsHashCode extends BugChecker implements NewClassTreeMatcher {
private static final String URL_CLASS = "java.net.URL";
private static final Matcher<Tree> TYPE_MATCHER =
anyOf(
new URLTypeArgumentMatcher("java.util.Set", 0),
new URLTypeArgumentMatcher("java.util.Map", 0));
@Override
public Description matchNewClass(NewClassTree tree, VisitorState state) {
if (TYPE_MATCHER.matches(tree, state)) {
return describeMatch(tree);
}
return Description.NO_MATCH;
}
private static class URLTypeArgumentMatcher implements Matcher<Tree> {
private final String clazz;
private final int typeArgumentIndex;
URLTypeArgumentMatcher(String clazz, int index) {
this.clazz = clazz;
this.typeArgumentIndex = index;
}
@Override
public boolean matches(Tree tree, VisitorState state) {
Symbol sym = state.getSymbolFromString(clazz);
if (sym == null) {
return false;
}
Type type = ASTHelpers.getType(tree);
if (!ASTHelpers.isSubtype(type, sym.type, state)) {
return false;
}
Types types = state.getTypes();
Type superType = types.asSuper(type, sym);
if (superType == null) {
return false;
}
List<Type> typeArguments = superType.getTypeArguments();
if (typeArguments.isEmpty()) {
return false;
}
return ASTHelpers.isSameType(
typeArguments.get(typeArgumentIndex), state.getTypeFromString(URL_CLASS), state);
}
}
}